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PTFE - main valve seat ring material

The main valve seat ring material is polytetrafluoroethylene (PTFE). It almost all the chemical substances are inert, and has a coefficient of friction is small, stable performance, easy to aging, wide applicable temperature and sealing performance of the integrated features. However, the physical properties of PTFE has a higher coefficient of expansion, the sensitivity of the cold and poor thermal conductivity, the valve seat seal must be designed around these characteristics. The valve seat seal plastic materials, including PTFE family and filled PTFE, nylon and other materials. However, when the sealing material hardens, the reliability of the seal will be destroyed, especially in the case of low dropout voltage. In addition, synthetic rubber such as nitrile rubber, can also be used as a seat material, but it applies to media and use temperature range is restricted. In addition, no lubrication, the use of synthetic rubber easy to get stuck sphere.